T Docket 99-87 (FCC 03-34, FCC 04-292), the Commission adopted new frequency plans and transition provisions for transmitters operating pursuant to Part 90 of the FCC Rules. The new rules prohibit Equipment Authorization of devices with 25 KHz bandwidth in the Part 90 refarming (narrowbanding) frequency bands 150-174 and 421-512 MHz after 12/31/2010 (the transition date), unless the equipment meets the efficiency standards discussed below. A reminder Public Notice about the deadlines, FCC DA 09-2589, was released 12/11/2009.
An Order released by the Commission (DA 12-642, April 26, 2012) waives the requirement for Industrial/Business and Public Safety Radio Pool licensees in the 470-512 MHz (T-band) to migrate from 25 kHz mode to a 12.5 kHz or other spectrally efficient technology. For the equipment operating in this band the prohibition on the continued manufacture and importation of equipment capable of operating with only one voice path per 25 kHz of spectrum has been waived. An Order on Reconsideration (DA 12-1743, November 30, 2012) waives the prohibition on Certification of new equipment operating in wide-band mode in the T-band. Additional reminder Public Notices (DA 12-1914, November 30, 2012 and DA 13-367, March 14, 2013) were published providing additional clarification on recent narrowbanding issues.
A recent Order released by the Commission (DA 13-431, March 18, 2013 and Erratum DOC-319771) waives the requirements of §90.203(j) (5) for devices to support 6.25 kHz per voice channel modes and as a result the requirments §90.203(j) (4) (ii) that 12.5 kHz voice channels to be multi-mode. The waiver applies only to voice channels and does not affect the narrowbanding spectral efficiency for data requirements. The waiver permits two voice channels in a 25 kHz BW and one voice channel in a 12.5 kHz BW. The waiver is effective as of March 18, 2013 and expires on January 1, 2015.
The current policy to address this timeline is:
Applications for new equipment authorizations received by the Commission before the transition date can be granted with a wideband (25 KHz) emission designator as long as the equipment also has a narrowband (12.5 KHz and/or 6.25 KHz) emission designator. Applications for data rates less than 4800 bps under §90.203(j) (8) are on the Permit-but-Ask List and must be submitted to the FCC (Refer to KDB 388624). For grants of new devices that are required to meet the efficiency requirements the following note code should be added to each applicable line entry of the grant: ES- This equipment is capable of supporting a minimum data rate of 4800 bits per second per 6.25 kHz of channel bandwidth.
Special Cases: Applications for new equipment authorization received after the transition date will not be granted with a wideband emission designator unless they are intended to meet certain specific rules as discussed below.
(i) Section 90.203(j)(5) for special provisions of spectrum efficiency standards, or
(ii) Section 90.203(j) (7) for one way paging channel standards, or
(iii) Section 90.203(j)(8) for slower data rate where case-by-case consideration is necessary, (Note: For devices approved under this section of the rules the following note code should be added to the grant: J8 - This device has been authorized under 90.203(j)(8) with a data rate of less than 4800 bits per second per 6.25 kHz of channel bandwidth based on information submitted justifying why the slower data rate provides more spectral efficiency than the standard data rate, or
(iv) Subject to specific waivers issued to licensees or grantees.
The filing should clearly describe how the appropriate spectral efficiency standards are achieved and provide an attestation from the applicant indicating compliance with the rules.
The efficiency standard for digitized voice can be satisfied either by having multiple emissions such as four separate emissions on a 25 kHz channel or have multiple voice channels on a single emission (e.g.:, TDMA). The Ritron Waiver (DA 13-431) permits one voice channel per 12.5 kHz BW and waives the multi-mode requirement of §90.203(j)(4)(ii). The efficiency standard for data for single bandwidth mode or multi-bandwidth mode devices requires at least 4800 bps per 6.25 kHz of bandwidth or 9600 bps per 12.5 kHz channel. A 25 kHz single mode device must have a single emission rated at 4 x 4800 bps or a mode that has four individual but simultaneous emissions at 4800 bps per emission. Radios designed to operate on a 6.25 kHz channel do not need to meet the 4800 bps efficiency standard.
Permissive Changes: A Class I permissive change may not be used to change the emission designator of any device. Applications for a Class II permissive change may be submitted for any modification that meets the definition of a permissive change (Refer to KDB 178919). In general, applications for Class II permissive changes for wideband-only equipment will not be accepted after the final transition date (January 1, 2013) and after the final transition date (January 1, 2013), all applications for permissive changes will be granted without the wideband emission designator and any such emissions should be disabled. A device that supports mulit-mode capability or meets the spectrum efficiency standards of Section 90.203(j) (5) may continue to have the wideband emission designation as explained above). For permissive change grants for devices that are required to meet the efficiency requirements, the following note code should be added to each applicable line entry of the grant: ES- This equipment is capable of supporting a minimum data rate of 4800 bits per second per 6.25 kHz of channel bandwidth.
Permissive Change Example: Equipment is approved for 25/12.5 KHz operation prior to the transition date. After the transition date a component unrelated to the power output or frequency determining circuitry becomes unavailable and must be replaced with a similar component. The change meets the 2.1043 definition of a permissive change and the device is tested to determine if a Class I or Class II permissive change is appropriate. If the test results show a Class I change is acceptable, then the process is complete and the new device may be marketed. If the test results show a Class II permissive change is required, an application is then submitted to the FCC or a TCB. When a permissive change is filed for 25/12.5 KHz equipment the FCC requires the device to show compliance with the spectral efficiency standards of Section 90.203(j) (5).
Software Change to Remove Emission: When a software change is made to a device to remove an approved operating mode/emission designator, no permissive change is required unless the device was approved as a Software Defined Radio. If the device was approved as a software defined radio, a Class III permissive change must be filed with the Commission.
An updated reminder Public Notice (DA 10-2294) was issued on December 6, 2010. This updated reminder provides a link to the FCC Public Safety and Homeland Security Bureau (PSHSB) VHF/UHF Narrowbanding Information web site which contains general refarming information as well as information on frequency coordination and Grant Programs. (See http://www.fcc.gov/pshs/public-safety-spectrum/narrowbanding.html).
Attached to this publication are two documents: (1) a series of questions and answers 579009 D01 - Q and A on Re-farming Part 90 freq v03r01 and (2) a narrowband transition summary table 579009 D02 Transition Summary Table v01r02.